To the Editor:—  Although we find the two studies by Naguib et al.  1and Kopman et al.  2to be theoretically interesting, we believe that it is dangerous to link them with our everyday anesthetic practice.

The data sheet for Scoline (Evans Medical, Surrey, United Kingdom), 3which used to be one our available preparations of succinylcholine in the United Kingdom, states in its precautions that “Scoline  must never be given when there is doubt about the ability to ventilate the lungs.” In keeping with this, it has never been our practice to rely on the short duration of action of succinylcholine as a “get-out clause” in the event of a failed rapid sequence intubation.

The wide variability in a patient’s breakdown of succinylcholine is well known, and surely both of these studies show that using a lower dose of succinylcholine makes an intubation attempt more likely to fail. There may then still be the problem of prolonged paralysis.

Because a successful intubation is of paramount importance in this group of patients, we want to have the best intubation conditions. Therefore, on the basis of these studies, we believe it would be more clinically relevant to have studied the effects on the intubating conditions of using a higher dose of succinylcholine than the standard dose of 1.0 mg/kg rather than studying lower doses.

Naguib M, Samarkandi A, Riad W, Alharby SW: Optimal dose of succinylcholine revisited. Anesthesiology 2003; 99:1045–9
Kopman AF, Zhaku B, Lai KS: The “intubating dose” of succinylcholine: The effect of decreasing doses on recovery time. Anesthesiology 2003; 99:1050–4
Scoline [data sheet]. ABPI compendium of data sheets and summaries of product characteristics 1996–7, pp 317–8. Datapharm Publications Ltd., UK